A piezoelectric actuator is known as an example of an actuator which discharges droplets from a discharge port. The piezoelectric actuator includes a vibrating plate, a piezoelectric ceramic layer which is laminated on the vibrating plate, and a surface electrode which is disposed on the surface of the piezoelectric ceramic layer. When the piezoelectric actuator is used in a liquid discharge apparatus, the piezoelectric actuator is disposed on a pressure chamber member which includes a liquid pressure chamber. The surface electrode faces the liquid pressure chamber through the piezoelectric ceramic layer and the vibrating plate. When a drive signal is applied to the surface electrode, the piezoelectric ceramic layer and the vibrating plate are deformed and pressure is applied to a liquid contained in the liquid pressure chamber.
According to the above-described actuator, a deformation layer is deformed plural times. Therefore, there is a concern that a crack is generated in the actuator. If the crack reaches the surface of the electrode from a liquid channel, there is a concern that liquid leaks from the surface of the electrode and a short circuit may occur between the electrode and other conductive portions.